Recommended weaving patterns and torch
positions for vertical up and vertical down are shown in
Figure 7- 17.
With vertical up, for a square edge preparation an in-line, back-and-forth
weave is used. For a bevelled, multipass
joint a U pattern is used for the root. The fill and cover passes
are made using a side-to-side weave
with a backstep at the walls. The length of the backstep is on the order of a
wire diameter. For a vertical
up fillet a Christmas Tree pattern is used with pauses at the side
walls. For vertical
down an inverted U pattern is used, pausing at the side walls for
the root, fill, and cover passes.
Always take care in vertical down welding to keep the arc on the leading edge
of the puddle. Preventing
the molten metal from running ahead of the arc will improve weld soundness.
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